A moth-shaped robot built by engineers in Estonia and Italy can grow a new UV sensor on its own body, using chemicals carried in its artificial blood. Researchers at the University of Tartu and the Italian Institute of Technology report in the journal Advanced Science that shining ultraviolet light on a patch of the robot's printed wing turns that patch into a conductive material that senses later UV exposure.
The robot's transparent 3D-printed body is laced with veins, through which a small pump pushes about 3 ml of liquid. Some of the fluid seeps roughly a hundredth of a millimetre into the surrounding plastic, carrying pyrrole, a chemical that becomes the electrically conductive plastic polypyrrole when hit by UV light, aided by a light-activated additive. With a stencil, the team selected which patch of wing to light up, and that patch turned black. Gold wires threaded through the body during printing pick up the change: whenever UV light hits the patch, its electrical resistance briefly drops, and an onboard chip responds by blinking an LED or flapping the wings.
Robots that build or mend parts of themselves have been demonstrated before, including a soft robot that healed itself and a climbing robot that 3D printed its own body. The Tartu team's contribution, as PhD student Kadri-Ann Pankratov, first author of the study, put it, is circulation adding a function the robot never had: 'Growing the receptor on site means the environment itself can pattern the robot, based on what is actually happening at that time.'
The prototype cannot fly; its wings are moved by a nitinol wire heated by an external power supply. Pankratov said powering the wings with batteries would be possible, but the real benefit would come from energy stored in the blood itself, and the team has run initial tests to power the onboard microprocessor from reagents in the fluid. The researchers, not the robot, decided when to fill the veins, and a stencil, not the environment, decided where the sensor formed. The reaction cannot be undone. Pankratov said the real limit is not how many sensors the moth can grow, but how much of its body the fluid and light can reach.
The sensor still worked after four months in storage and grew more sensitive with each exposure as leftover pyrrole kept reacting, though it takes about five minutes to settle after each flash of UV. The same veins could later carry other chemicals, possibly reversible ones. Pankratov said: 'The benefit of having an on-board circulatory system would be that it can indeed be flushed and reused with the same mixture or something different entirely.' She added that she hopes in 10 years artificial robot blood and circulatory systems will be an obvious choice for some applications.
Analysis
Why This Matters
- Robots sent to collapsed buildings or other planets, where nobody can predict what they will need, could grow the sensors they require on site rather than arriving with a fixed set.
- The approach turns a robot's circulatory system into a construction system, letting the environment help pattern the machine.
- The same fluid may eventually power the robot's electronics; the team has begun initial tests of running the onboard microprocessor from reagents in the blood.
Background
Self-building and self-repairing robots are an established line of research, with earlier examples including a soft robot that healed its own damage and a climbing robot that 3D printed its own body. The Tartu robot is distinct in using an internal circulation system to add a new sensing function after manufacture: a liquid pumped through printed veins carries chemicals that react to UV light, and a stencil decides which patch of the body turns into a conductive sensor. The technique remains at prototype stage, requiring external power for the wings and researcher control over when and where growth happens.
What to Watch
- Whether the researchers extend the system to other chemicals and to reversible reactions, which Pankratov said the veins could support by being flushed and reused.
- Whether the circulatory system can power the onboard microprocessor without an external supply, an avenue the team says it has begun testing.
- Whether the approach moves toward field use, with Pankratov expecting artificial robot blood and circulatory systems to become an obvious choice for some applications within 10 years.
Checked
12 claims in this story checked against 1 source: 11 supported.
Show each claim
- SupportedThe robot moth grows a UV sensor on its own body using artificial blood.New Atlas: Technology-Innovation-Outdoor News: “this robo-moth can. Built by engineers at the University of Tartu in Estonia and the Italian Institute of Technology (IIT), it carries chemicals in its artificial blood that soak into its 3D-printed body when the team shines ultraviolet light on it, turning that patch of plastic into a brand-new sensor.”
- SupportedResearchers say growing receptors on site could help robots adapt to unpredictable environments.New Atlas: Technology-Innovation-Outdoor News: “That kind of self-construction is pretty useful when robots are sent where nobody can predict what they'll need, from collapsed buildings to other planets.”
- SupportedEngineers at the University of Tartu and the Italian Institute of Technology published the study in Advanced Science.New Atlas: Technology-Innovation-Outdoor News: “Built by engineers at the University of Tartu in Estonia and the Italian Institute of Technology (IIT)”
- SupportedPankratov said: “Growing the receptor on site means the environment itself can pattern the robot, based on what is actually happening at that time.”New Atlas: Technology-Innovation-Outdoor News: “"Growing the receptor on site means the environment itself can pattern the robot, based on what is actually happening at that time."”
- Partly supportedPankratov described circulation as the Tartu team's contribution that adds a function the robot never had.New Atlas: Technology-Innovation-Outdoor News: “The Tartu moth uses its circulation to add a function it never had.”
- SupportedA small pump pushes about 3 ml of liquid through the robot's veins.New Atlas: Technology-Innovation-Outdoor News: “A small pump pushes about 3 ml (0.1 fl oz) of liquid through them”
- SupportedSome fluid seeps about a hundredth of a millimetre into the surrounding plastic, carrying pyrrole that UV light and a light-activated additive turn into conductive polypyrrole.New Atlas: Technology-Innovation-Outdoor News: “some of it seeps about a hundredth of a millimeter into the surrounding plastic. That liquid carries pyrrole, a chemical that turns into an electrically conductive plastic called polypyrrole when it's hit by UV light, with help from a light-activated additive.”
- SupportedWhen UV hits the patch, its resistance briefly drops and an onboard chip can blink an LED or flap the wings.New Atlas: Technology-Innovation-Outdoor News: “whenever UV light hits the patch, its electrical resistance drops for a moment, and a small onboard chip responds by blinking an LED or flapping the wings.”
- SupportedThe prototype cannot fly, and its wings are moved by a nitinol wire heated by an external power supply.New Atlas: Technology-Innovation-Outdoor News: “It can't fly, and its wings are bent by a wire of nitinol, a shape-memory alloy heated by an external power supply.”
- SupportedThe team has run initial tests to power the onboard microprocessor from reagents in the fluid.New Atlas: Technology-Innovation-Outdoor News: “The team has run initial tests to power the onboard microprocessor from reagents in the fluid.”
- SupportedResearchers, rather than the robot, decided when to fill the veins, and a stencil rather than the environment determined where the sensor formed.New Atlas: Technology-Innovation-Outdoor News: “the researchers, not the robot, decided when to fill the veins, and a stencil they set, not the surroundings, decided where the sensor formed.”
- SupportedPankratov said the veins could be flushed and reused with the same or a different mixture.New Atlas: Technology-Innovation-Outdoor News: “"The benefit of having an on-board circulatory system would be that it can indeed be flushed and reused with the same mixture or something different entirely," explains Pankratov.”
